Knife-edge pivot for scale-beams



(No Model.)

F. H. R-iOHARDS. KNIFE EDGE PIVOT FOR SCALE BEAMS.

No. 559,750. Patented May 5, 1896.

Wi 11 168563; fi 1720'611202":

ANDREW BJiRAKAM,PHOYO-UTKQWASHINGYOXJC UNITED STATES ATENT Fries.

FRANCIS ll. RICHARDS, OF HARTFORD, CONNECTICUT.

SPECIFICATION forming part of Letters Patent No. 559,750, dated May 5,1896.

Application filed January 31, 1896. Serial No. 577,553. (No model.)

To 60% whom it may concern:

Be it known that I, Framers H. Rronnnns, a citizen of the United States,residing at Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inKnife-Edge Pivots for Scale-Beams, of which the following is aspecification.

This invention relates to knife-edge pivots adapted for use inconnection with scalebeams and the like, the object being to prol vide astrong and serviceable device of this character and to provide simpleand efficient means for applying to and holding said knifecdge pivot inplace and against movement in all directions when in operative positionrelative to the scale-beam or other like device.

In the drawings accompanying and forming part of this specification,Figure 1 is a plan view with a part of the scale beam broken away tobetter illustrate the improved means for holding a knife-edge pivot inoperative position thereon. Fig.2 is an end elevation of the same. Fig.3 is a transverse section on the line 3 3, Fig. 2. Fig. 4 is a sectionalplan view of a part of the scale-beam, a knife-edge pivot, and a-lockertherefor, the knife-edge pivot having been placed in the receiving-boretherefor formed in the scalebeam and ready to be forced to the operativeposition. Fig. 5 is a similar view, the knife-edge pivot beingillustrated in the operative position thereof on the scalebeam and heldin such position by a locker or locking device. Fig. Gis transversesection of the scale-beam, a knife-edge-pivot means for holding thelatter against rotative and endwise movement being also illustrated, apart of the pivot being broken away to better show said holding means.Fig. 7 is a detail view of the knife-edge pivot, and Fig. 8 is atransverse section on the line 8 8 thereof. Figs. 9 and 10 are detailviews, in end elevation and in central longitudinal section,respectively, of the locker or locking device.

Similar characters of reference designate like parts in all the figuresof the drawings. The knife-edge pivot consists of a body portion and aknife-edge portion or knife-edge proper, and by the term body portion ofthe knife-edge pivot is meant thatpart thereof which is located in abearing or otherwise tion or knife-edge proper is meant that part of theknife-edge pivot on which is located a V or other bearing-for example,in the manner disclosed in Letters Patent No.

5%,840, granted to me October 29, 1895.

A portion of a scale-beam is illustrated at B transversely bored, thebores thereof constitutin g bearings for receiving the knife-edgepivots, which are designated, respectively, by P and P, the cylindricalbody portions 21 of the latter being journaled or located in saidbearings. The cylindrical body portions 21 of the knife-edge pivots areso fitted in the bearings thereof that said knife-edge pivots may befreely removed therefrom by the application of ordinary hand-pressure,but are not so loosely held as to induce wabbling.

The knife-edge pivot P is illustrated supported by a suitable support orbearing, (see Fig. 3,) illustrated as a double-V bearing and located onthe knife-edge portion thereof, said V-bearing being carried by the baseof the weighing-machine, and the knife-edge pivot I" constituting abucket-support for supporting a similar double-V bearing 20, carried bythe bucket or by a hanger thereon.

The knife-edge pivots P and P, it will be understood, are removablysecured by the scale-beam, and hence are made interchangeable, so thatthey may be easily and quickly removed for sharpening or grinding theknifeedges 22 thereof when dulled and as quickly and easily applied inplace, improved means, to be hereinafter described, being employed forsetting said knife-edge pivots in absolutely true and accuratepositions, these re sults being attainable by ordinary unskilled labor.

As the two knife-edge pivots P and P are the same in all materialrespects, I deem it necessary to describe in detail but one of saiddevices-for example, the knife-edge pivot P, the same characters ofreference being used to designate corresponding parts on the knife-edgepivot P.

Vith the ordinary type of knife-edge pivot it often happens that thesebreak or snap off at that part thereof which is subjected to thegreatest stress, and to guard against and prevent such accidents areinforced portion extending obliquely away from the knife-edge 22 atthe end of the body portion 21 and outwardly from said body portion isprovided, such reinforced portion being illustrated at 12. By reason ofsuch reinforcement of the knife-edge pivot the latter will be ofgreatest cross-sectional area adjacent to the body portion, thisgradually decreasing outwardly therefrom and will effectually resist allstress applied thereto.

The knife-edge pivot P is illustrated consisting of twooppositely-disposed knife-edge portions 22, which, when said knife edgepivot P is in its operative or working position relatively to thescale-beam 13, should equidistantly project from the opposite facesthereof, and great care should be exercised in placing or setting thesepivots or knifeedges' in position.

It will be evident that, and for the purpose, hereinbefore mentioned,these knife-edge pivots must be occasionally removed, and it will beapparent that with the ordinary types of knife-edge pivots theemployment of skilled labor is necessary to properly reset the same.

My invention contemplates the provision of means for setting andresetting these knifeedge pivots in true and accurate positions withoutthe intervention of skilled labor, and when in such positions positivelyholding the same against lateral an d endwise movements, said pivotsbeing, as heretofore stated, interchangeable.

An actuating-locker or locking device is illustrated at 13 carried bythe scale-beam, and when in its normal position is seated in an opening13, formed therein, this device serving a dual function-that of a lockand of an actuator. This actuatinglocker or locking device 13 isoperable for engaging the knife-edge pivot P, and when the former isdriven or forced into its opening in the scale-beam or from its normalposition therein the pivot P will be carried therewith. In theembodiment illustrated this actuatinglocker 13 is in the form of aheaded screw, the opening in the scale-beam therefor having an internalthread for receiving said screw, the head or stop 14. of saidactuatinglocker 13, when said screw is in its normal position, lying ina seat or counterbored opening 15, formed in the face of the scalebeam,against the inner wall of which opening the stop let abuts when thescrew has reached the limit of its inward movement, thereby indicatingthat the knife-edge pivot P has been properly set.

The body portion 21 of the knife-edge pivot is illustrated provided witha notch 16, transversely formed therein, into which the head or stop 14of the screw 13 enters, so that when the latter is forced into or out ofits opening or seat in the scale-beam B the knife-edge pivot P will becarried therewith. The slot 13" of the head 14: of the screw 13 does notextend entirely across said head, so that as said screw is screwed intoor out of its opening no rough or uneven surfaces are presented by saidhead 14 to the walls .of the notch 16 for abrading the same.

Means are provided also for limiting the rotative or lateral movement ofthe knifeedge pivot Pin its bearing in the scale-beam B, and such meansare shown consisting of a gage-key separable therefrom, and which isadapted to be seated in a keyway or notch formed in the pivot. Such akey is illustrated at 17 and in practice will be formed ofhighly-tempered steel, it being subjected to considerable lateral andlongitudinal pressures during the operation of the weighing- Inachine.The keyway in the knife edge pivot for receiving said gage-key 17 isillustrated at 18 and is illustrated longitudinally disposed, beingformed in the cylindricalbody portion 21 thereof, and as also extendinga short distance beyond said body portion to better adapt the knife-edgeportion 22 to be ground throughout its entire surface.

The keyway 18 is complementary to a key way formed in the scale-beam andextending into the knife-edge-pivot bearing, said lastmentioned keywaybeing illustrated at 1!) extending transversely of the scale-beam. Thegage-key 17 is adapted to be seated in these keyways formed,respectively, in the scale-beam B and the body portion of the knife-edgepivot P, and said keyways will be in alinement when the knife-edge pivotP is in its operative or working position. The in ner wall of the keywayor notch 18, formed in the body portion of the knife-edge, willpreferably be curved, and the key 17, which is seated in said keyway, isillustrated as also curved, the curvature thereof being concentrio withthat of the inner wall of said keyway, so that when said members are inoperative positions thereof, as indicated in Figs. 1, 2, and 6, theengagement of these members limits also the longitudinal movement of theknife-edge pivot P in its bearing, the locker 13 in turn holding saidknife-edge pivot firmly in place against longitudinal movement.

On reference to Figs. 3 and 2 (see dotted lines, Fig. 2)thc V-bearingsthere illustrated as located on the knife-edge pivots P and P are doubleor bifurcated. It will also be ob served on reference to Figs. 1 and 3that the key 17 for the knife-edge pivot P is illustrated projectingbeyond the opposite faces of the scale-beam B to thereby constitute endstops, whereby lateral movement of the scale-beam will be limited duringthe operation of the weighing-n1aohine by the abutment of said V-bearingagainst the projecting key. This operation also tends to firmly maintainthe key 17 in its seat in the keyways formed, respectively, in theknife-edge pivots P and P and the scale-beam B, the latter keywaysextending, as hereinbefore pointed out, into the bearings of saidpivots.

Having thus described my invention, what I claim is- 1. The combinationwith a scale-beam hav- ITO ing a bearing and an opening, of a knife-edgepivot located in said bearing; and a lockingactuator for engaging saidpivot, and having a movement into and out of said opening, whereby whensaid locking-actuator is forced into or out of place, the knife-edgepivot will be carried therewith.

The combination with a scale-beam having a bearing and an opening, of aknife-edge pivot located in said bearing, said pivothaving' a notch; anda headed locking-actuator, the head of which is adapted to enter thenotch in said knife-edge pivot, said lockingactnator having also amovement into and out of said opening, whereby when saidlocking-actuator is forced into or out of place, the knife-edge pivotwill be carried therewith.

3. The combination with a scale-beam having a bearing, of alongitudinally-notched knife-edge pivot journaled in said bearing, and11 avin g the inner wall of the notch thereof curved; and a key seatedin said notch, and having a part thereof curved concentric with thecurvatureof the inner wall of said notch and in engagement therewith.

e. The combination with a scalebeam having a bearing, and a keywa-yextending into said bearing, of a knife-edge pivot located in saidbearing and having a longitudinally-disposed keyway therein; a keyseated in said keyways and projecting beyond the opposite faces of thescale-beam to thereby constitute end stops; and a double-V bearinglocated on the knife edges of said pivot.

5. The combination with a scale-beam having a bearing, and having akeyway extend ing into said bearing, and havin g also an opening of aknife-edge pivot located in said hearing, and having a complementarykeyway therein; a key seated in said keyways to thereby limit thelateral movement of said knifeedge pivot in its bearing; and alocking-actuator for engaging said pivot, and having a movement into andout of said opening in the scale-beam, whereby when said actuator isforced into or out of place, the knife-edge pivot and the key thereforwill be carried therewith.

6. The combination with a scale-beam having a bearing, of a knife-edgepivot located in said bearing; and a locking-actuator for saidknife-edge pivot.

FRANCIS H. RICHARDS.

YVitnesses:

FRED. J. DOLE, HENRY BIssELL.

